[Localization of lesions in aphasia: clinical-CT scan correlations (Part 1)]

Using a microcomputer, the locus and extent of the lesions, as demonstrated by computed tomography for 127 cases with various types of aphasia were superimposed onto standardized matrices. The relationship between the foci of the lesions and the types of aphasia was investigated. Broca ++aphasics (n = 39): Since the accumulated site of the lesions highly involved the deep structures of the lower part of the precentral gyrus as well as the insula and lenticular nucleus, only 60% of the Broca aphasics had lesions on these areas. This finding has proved to have little localizing value. Wernicke aphasics (n = 23): The size of the lesion was significantly smaller than Broca's aphasia. At least 70% of the patients had the superior temporal lesions involving Wernicke's area and subcortical lesions of the superior and middle temporal gyri. The site of lesion corresponded roughly to the previous clinico-pathological reports but located a little deep. Amnestic aphasics (n = 18): The size of the lesion was smaller than any other types. While there was some concentration of the lesions (maximum 40%) in the area of the subcortical region of the anterior temporal gyrus adjacent to Wernicke's area and the lenticular nucleus, the lesions were distributed throughout the left hemisphere. Amnestic aphasia was thought to be the least localizable. Conduction aphasics (n = 11): The lesions were relatively small in size. Many patients had posterior speech area lesions involving at least partially Wernicke's area. In particular, more than 80% of the conduction aphasics had lesions of the supramarginal gyrus and it's adjacent deep structures. Global aphasics (n = 36): In general, the size of the lesion was very large and 70% of the global aphasics had extensive lesions involving both Broca's and Wernicke's areas. However, there were observations showing that the lesions can be small and confined. Because of the large variability in lesion patterns and speech disturbances, it is necessary to expand the number of cases for relate detailed neuropsychological examinations with morphological CT-findings. Our method permits it easily to process and to analyze a large number of cases. By studying larger series, the better definition in the relationship between anatomic lesion location and aphasia type, even for less common aphasia syndromes could be obtained.